长沙市开福区36~54月龄儿童户外活动时间和屏幕时间与睡眠关系的出生队列研究

Association of outdoor activity time and screen time with sleep for 36 to 54 months children in Kaifu District,Changsha:A birth cohort study

目的:近年来中国儿童睡眠问题的流行率不断上升,目前存在身体活动与睡眠的关系不一致及屏幕时间对低龄儿童睡眠的影响似乎更显著的观点。本研究旨在了解长沙市开福区36~54月龄儿童户外活动时间、屏幕时间和睡眠(睡眠总时长、就寝时间、早上醒来时间)的现状,探讨36~54月龄儿童户外活动时间和屏幕时间与睡眠的关系。方法:采用整群抽样的方法,选取2015年1月至12月在长沙市开福区3个社区卫生服务中心分娩的1 286名新生儿为研究对象,建立前瞻性出生队列。采用自行设计的调查问卷通过入户随访的方式收集儿童在36、42、48、54月龄时的资料,应用混合线性模型探讨户外活动时间和屏幕时间与睡眠的关系。结果:36~54月龄儿童的睡眠总时长从11.60 h/d减少到10.92 h/d(P<0.001);就寝时间从21:58延迟到22:00(P=0.124);早上醒来时间从7:52提前到7:37(P<0.001);户外活动时间从2.58 h/d减少到1.94 h/d(P<0.001),屏幕时间从1.28 h/d减少到1.09 h/d(P<0.001)。随着年龄增加,儿童睡眠总时长<10 h/d和户外活动时间<2 h/d发生率存在增加的趋势,屏幕时间≥1 h/d的发生率存在下降的趋势(P<0.05)。混合线性模型结果显示户外活动时间增加与睡眠总时长增加(β=0.22,95%CI:0.00~0.44)和早上醒来时间延迟(β=0.16,95%CI:0.00~0.32)有关,屏幕时间增加与就寝时间(β=0.22,95%CI:0.05~0.39)和早上醒来时间延迟(β=0.24,95%CI:0.08~0.41)有关,且这些关联在性别上存在差异,男童较长的户外活动时间与其早上醒来时间延迟(β=0.37,95%CI:0.14~0.59)有关,而女童与其早上醒来时间(β=-0.16,95%CI:-0.33~0.01)的关系无统计学意义。女童较长的屏幕时间与其就寝时间(β=0.40,95%CI:0.09~0.63)和早上醒来时间延迟(β=0.33,95%CI:0.15~0.51)有关,而男童只与其早上醒来时间延迟(β=0.29,95%CI:0.06~0.52)有关,关联程度低于女童。结论:长沙市开福区36~54月龄儿童存在晚睡晚起、户外活动不足及屏幕使用时间过长的问题,户外活动时间和屏幕时间与睡眠有关,增加户外活动时间和减少屏幕时间有助于改善学龄前儿童的睡眠。

Objective: The prevalence rate of sleep problems in children in China is increasing in recent years. There are inconsistencies in the relationship between physical activity and sleep, and the impact of screen time on young children seems more obvious. This study aims to understand the current situation of outdoor activity time, screen time and sleep(total sleep duration, bedtime, and wake-up time) and the associations between outdoor activity time and screen time with sleep for children aged 36-54 months in Kaifu District of Changsha.Methods: Using the cluster sampling method, 1 286 newborns delivered in 3 community health service centers in Kaifu District, Changsha from January to December 2015 were selected as the research subjects to establish a prospective birth cohort. According selfdesigned questionnaire and household follow-up to select 36, 42, 48, 54 months Children’s data. The mixed linear model was used to explore the associations of outdoor activity time and screen time with sleep.Results: The 36-54 months children’s total sleep duration was decreased from 11.60 h/d to 10.92 h/d(P<0.001);bedtime time delayed from 21: 58 to 22: 00(P=0.124);wake-up time advanced from 7:52 to 7:37(P<0.001);outdoor activity time was decreased from 2.58 h/d to 1.94 h/d(P<0.001), and screen time was decreased from 1.28 h/d to 1.09 h/d(P<0.001). With aging, the prevalence of sleep <10 h/d and outdoor activity time <2 h/d was increased significantly, and the prevalence of screen time ≥1 h/d was decreased(P<0.05). Mixed linear models showed that longer outdoor activity time was related to increased total sleep duration(β=0.22, 95% CI 0.00 to 0.44) and delayed wake-up time(β=0.16, 95% CI 0.00 to 0.32), and longer screen time was related to delayed bedtime(β=0.22, 95% CI 0.05 to 0.39) and wake-up time(β =0.24, 95% CI 0.08 to 0.41). These associations were different in gender. Longer outdoor activity time was related to delayed wake-up time(β=0.37, 95% CI 0.14 to 0.59) in boys, but not in girls(β=-0.16, 95% CI-0.33 to 0.01). Longer screen time was associated with delayed bedtime(β=0.40, 95% CI 0.09 to 0.63) and wake-up time(β=0.33, 95% CI 0.15 to 0.51) in girls, but only related to delayed wake-up time(β=0.29, 95% CI 0.06 to 0.52) in boys, and the degree of association was lower than that of girls.Conclusion: Among children aged 36-54 months in Kaifu District, Changsha, there are problems including going to bed late and getting up late, insufficient physical activity, and long screen time. Outdoor activity time and screen time are related to sleep. Increasing outdoor activity time and reducing screen time can help to improve children’s sleep.